Fish egg sorting apparatus

ABSTRACT

Fish egg sorting apparatus comprising a rotated disc provided with a series of holes extending through the disc adjacent its peripheral surface, each hole capable of containing two fish eggs, photoelectrical means for scanning two eggs at the same time, one of the two eggs being carried in the front end of a hole and the other of the two eggs being carried in the rear end of another hole, and means activated when a dead egg is scanned for ejecting the dead egg from its hole. A glass shield is located closely adjacent the periphery of the disc, between the rotating disc and scanning means, for preventing water from spattering on the scanning means and for holding a water bead between the disc and scanning means providing a clear path through which a light beam from the electrical means passes to eggs in the disc, said water bead preventing formation of film on either the shield or disc which might interfere with passage of the light beam.

United States Patent 72] Inventor Neil Van Gaalen R0. Box 578, GlenwoodSprings, Colo. 81601 [21] Appl. No. 27,862 [22] Filed Apr. 13, 1970 [45]Patented Oct. 19, 1971 [54] FISH EGG SORTING APPARATUS 14 Claims, 14Drawing Figs.

[52] U.S. Cl 209/1l1.6, 209/111.7, 250/223, 356/53 [51] Int. Cl B07c5/342 [50] Field of Search 209/111.6, 111.7; 250/223; 356/53 [56]References Cited UNITED STATES PATENTS 3,297,157 1/1967 Jensen209/111.7X 3,517,807 6/1970 Van Gaalen 209/111.7 X

Primary ExaminerRichard A. Schacher Attorney-Bertha L. MacGregorABSTRACT: Fish egg sorting apparatus comprising a rotated disc providedwith a series of holes extending through the disc adjacent itsperipheral surface, each hole capable of containing two fish eggs,photoelectrical means for scanning two eggs at the same time, one of thetwo eggs being carried in the front end of a hole and the other of thetwo eggs being carried in the rear end of another hole, and meansactivated when a dead egg is scanned for ejecting the dead egg from itshole. A glass shield is located closely adjacent the periphery of thedisc, between the rotating disc and scanning means, for preventing waterfrom spattering on the scanning means and for holding a water beadbetween the disc and scanning means providing a clear "path throughwhich a light beam from the electrical means passes to eggs in the disc,said water bead preventing formation of film on either the shield ordisc which might interfere with passage of the light beam.

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ATTOR EY FISH EGG SORTING APPARATUS This invention relates to fish eggsorting apparatus for separating dead fish eggs from live eggs. Deadfish eggs are white in color and opaque, whereas live fish eggs arelight orange in color and transparent. Dead fish eggs must be separatedfrom the live eggs to avoid fungus from dead eggs attaching to the liveones and thereby killing the live eggs.

The main object of the invention is to provide apparatus which isexceptionally speedy in operation, capable of sorting the fish eggs at aspeed in excess of 100 eggs per second. This high speed, coupled withaccuracy in making the separation, is achieved by utilizing a rotateddisc provided with egg holes each of which holds two eggs, one egg beingautomatically removed from a hole without simultaneously removing theother egg in that hole.

In the preferred embodiment of the invention, the sorting operationtakes place at a single-sorting station adjacent the rotating disc whichincludes means for successively scanning the two eggs in one hole, andmeans for automatically rejecting the dead eggs, if any, at the site ofthe sorting station, permitting the good eggs to be moved with the discto a live egg removal station. In' a modified embodiment of theinvention, two sorting stations are employed, the first one for scanningone of the two eggs in a hole and for automatically rejecting the egg,if dead, into a bad egg container, and a second sorting station forscanning the other of the two eggs in that hole and for automaticallyrejecting the second egg, if dead, into a second bad egg container. Inthis modified embodiment, each of the two sorting stations includes alsoa good egg container for receiving the live eggs.

In either embodiment of the invention, similar electrical systems areused for operating the scanners which preferably are the reflective-typephoto electric units in which a light beam is directed to a fish eggwhich, if opaque to light, reflects the light beam back into thephotoelectric unit. The latter instantly actuates an air jet to blow thedead egg out of its hole. Air pressure is supplied by air compressorswhich may be separate from the sorting apparatus.

An electrical counter may be connected in parallel with the compressedair valves to provide an accurate count of the dead egg pickoff. Theconstruction of the containers in which the separated good and bad eggsare deposited is such that live eggs can be transferred directly intohatching trays without interrupting the operation of the sortingapparatus.

Another important advantage of the invention is the accuracy with whichthe scanners or sensors detect the dead eggs which are opaque to light.Heretofore the efficiency of photoelectric units used for this purposehas been adversely affected by water spray falling on the sensor lensfrom the peripheral edge of the rotating egg holding disc or from theair jets adjacent the disc. In the apparatus of this invention, 1 employa small glass shield mounted about 5/1000 inch from the edge of therotating disc, directly between the sensors and the peripheral edgesurface of the disc. The water carried by the rotating disc as well aswater spatter from the air jets forms an oblong water bead that fusesitself between the peripheral sur-. face of the disc and the shield. Thelight beam from the sensor shines through the shield, the water bead andthe transparent peripheral edge of the rotating disc for the purpose oftesting each eg as it passes the sensor. The 5/1000 inch space betweenthe shield and disc is exactly right to maintain a refreshed water beadand to prevent drying of the water into a film on the shield which wouldinterfere with the passage of the light beam from the sensor through theshield, while at the same time the shieldefficiently serves to preventwater spray from contaminating the sensor lens. Thus the light beam fromthe photoelectric unit passes efficiently through its lens, shield,water bead and peripheral edge surface of the disc to an egg in thedisc, and the beam reflected by an opaque egg likewise passesefficiently through the disc edge, water bead, shield and photocell lensto activate an air jet to effect removal of the dead egg.

The egg-holding holes in the rotated disc extend through the disc fromone major surface to the other and are designed to contain two eggs,side by side, between the two major surfaces. Since the disc rotatesabout a horizontal axis, one major surface may be called the front ofthe disc and the opposite surface may be referred to as the back of thedisc. One of two eggs located in one of the holes may be described asbeing in an annular row or track 1" adjacent the front of the disc andthe other of the two eggs may be described as being in a similar annularrow or track 2" adjacent the back of the disc.

When a single-sorting station is employed, two scanners or sensors areused in that station, one having its light beam directed to an egg intrack 1 and the other having its light beam directed to an egg in thesame hole but in track 2. A stop member is located adjacent the frontsurface of the disc in position to close a moving hole opening to thefront, and another stop member is located adjacent the rear surface ofthe disc in position to close the same moving hole opening to the backwhen the disc has rotated the circumferential distance between twoholes. Air jets communicate with a source of compressed air leading toeach hole through air openings in the backface of the disc to blow deadeggs out of the holes. When sensor for track 1 has detected a dead eggin track 1 of a hole, the air jet is activated to blow that egg out ofthe forward opening of the hole, but the egg in track 2 of the same hole(whether dead or alive) is not affected because the stop which closesthe rear opening of that hole prevents movement of the egg rearwardlyout of the hole. When the rotating disc has moved the same hole intoposition for the egg in track 2 to be scanned by the sensor, the air jetwill be activated if that egg is a dead egg, and will blow it out of thehole rearwardly due to the stop closing the forward opening. If it is agood egg, it will be carried by the disc until it reaches the live eggstation in which a continuously blowing air jet removes good eggs fromthe holes and permits them to fall into a suitable container for liveeggs.

Another object of the invention is to support the rotating disc in suchmanner that the eggs in the water and egg compartment are drawn into theholes in the disc and prevented from passing through or out of the holesprematurely. For this purpose, a combination backplate with a rib forclosing the rear opening of holes, together with a cradle for therotating disc are provided in the water and egg compartment. The cradleengages the lower portion of the peripheral edge of the disc immersed inthe water, and the rib covers the annular row of holes in that portionof the disc in the water. The rib is mounted on the backplate in suchposition as to contact the rear side surface of the disc opposite theegg holes. The backplate is provided with annular slots which permitsufficient flow of water through the backplate to draw the eggs into theholes in the disc. The cradle fits snugly against the periphery of therotating disc and prevents eggs from passing across that part of theperipheral edge which is submerged in the water. The eggs are drawn intothe holes in the disc and are carried by the disc upwardly above thewater level into the egg scanning zone, as heretofore described.

Another object of the invention is to provide means for washing thewalls of the sorted egg receiving compartments to carry the eggs throughtheir respective compartments and out through holes in the bottom of thesorter, the live eggs being carried to hatching trays withoutinterrupting the operation of the sorter.

In the drawings:

FIG. 1 is a perspective view of fish egg sorting apparatus embodying myinvention.

FIG. 2 is an elevational side view of the same.

FIG. 3 is an elevational view showing the front face of the rotating eggcarrying disc and the cradle located beneath the disc, together withother parts of the apparatus as viewed in the plane of the line 3-3 ofFIG. 4.

FIG. 3a is a fragmentary view of a detail of the disc and a shieldadjacent the periphery of the disc.

FIG. 4 is a top plan view of the apparatus with the electrical controlcabinet omitted.

FIG. 5 is an elevational front view on an enlarged scale, of thebackplate which is located adjacent the rear side of the egg-carryingdisc.

FIG. 6 is a top plan view of the backplate of FIG. 5, together with anannular rib which is attached to the front face of the backplate, andthe cradle located closely adjacent the front face of the rib beneaththe rotating disc.

FIG. 7 is an edge view, on an enlarged scale, of a portion of theperipheral edge of the egg carrying disc, showing two of theegg-containing holes which are equidistantly spaced circumferentially ofthe disc adjacent the disc periphery, and showing also a pair of stopmembers located adjacent opposite sides of the disc to close one of theholes at its rear opening and to close the other of the holes at itsfront opening.

FIG. 8 is a view similar to FIG. 7 showing air jets communicating withthe egg-containing holes and illustrating how one of two eggs in eachhole is blown out of the hole by the air jet.

FIG. 9 is an elevational view of a reflective-type photoelectric unit,showing diagrammatically how the light beam passes from the lamp of theunit to an opaque egg and is reflected back to the photoelectric cell inthe unit through the same lens.

FIG. 10 is a view similar to FIG. 3 but showing a modification of theapparatus.

FIG. 1 l is a top plan view of part of the construction shown in FIG.10.

FIG. 12 is an edge view, on an enlarged scale, of a portion of theperipheral edge of the egg-carrying disc used in the modified apparatusof FIGS. 10 and 11.

FIG. 13 is a diagram of the electrical circuits housed in the controlcabinet of the sorting apparatus.

The fish egg sorting apparatus shown in FIGS. 1-9 and the modifiedconstruction of FIGS. 10-12 comprises a water reservoir located in thefront end of the apparatus provided with water input means 21 tomaintain a water level indicated at 22 in FIG. 2. The water reservoir 20extends downwardly to the bottom 23 of the apparatus and has openings inits inner wall 24 for passage of water into the egg and watercompartment 25. An electrical control cabinet 26 is located on a support27 rearwardly of the egg and water compartment 25. The electricalcontrol means in the cabinet 26 will be described hereinafter inconnection with the diagram of FIG. 13. The water level in the egg andwater compartment is indicated by the broken line 28 in FIG. 2. Alsowithin the egg and water compartment is an assembly extendingtransversely of the compartment, consisting of a backplate 30, attachedannular rib 31, and cradle 32, as shown in broken lines in FIG. 2 and indetail in FIGS. 3-6. The backplate 30 is as high as the depth of thecompartment 25 and is provided with a plurality of arcuate slots 33which permit passage of water therethrough as shown in FIG. 5. The flatfaced arcuate rib 31 is fastened to the front face of the backplate 30in the arcuate space between the slots 33. The cradle 32 also is arcuatein shape and has an upper arcuate surface 34 which fits closely belowthe peripheral edge of a rotated egg-carrying disc 35. Spacers betweenthe backplate 30 and cradle 32 are designated 29.

An egg-carrying disc 35 is made of transparent material, circular inshape, having parallel front and rear major surfaces and a peripheraledge surface 36. The disc is mounted on a horizontal shaft 37 driven bya motor (not shown) in the cabinet 26. The disc is provided adjacent itsperipheral edge 36 with a plurality of holes 38 equidistantly spacedapart around the entire circumference of the disc. In a disc 12 inchesin diameter, approximately 100 holes 38 may be provided. The holes 38extend through the disc from one major surface to the other and thushave both front and rear open ends. Each hole is large enough to containtwo fish eggs located side by side, as best shown in FIGS. 7 and 8,where they are designated 40 and 41, respectively. The spaces in theholes 38 adjacent the front openings 42 form an annular row or "track 1"and the spaces in the holes 38 adjacent the rear openings 43 form anannular row or track 2." The function of this arrangement will beexplained in detail hereinafter. One of the holes 38 in the disc 25 hasa stop 44 located to close the front opening 42 in that hole, and theadjacent hole 38 in the disc 25 has a stop 45 located to close the rearopening 43 in that hole. An air duct 46 extends inwardly from the rearface of the disc 35 into each of the holes 38. Two air jets 47 directedtoward the rear face of the disc adjacent its peripheral edge 36 supplyair under pressure when activated by photoelectrical units about to bedescribed.

A sorting station located at the left of the compartment 25 comprisestwo photoelectrical units 50 and 51, of the reflective type, (one shownin FIG. 9), located adjacent the peripheral surface 36 of the rotateddisc 35, one above the other, the spacing being such that the lowersensor 50 has its light beam directed to egg 40 in track 1" in theforward opening side of the holes 38, while the upper sensor 51 has itslight beam directed to eg 41 in track 2 in the rearwardly opening sideof the holes 38. The sensors are spaced apart vertically to conform tothe spacing of two adjacent holes 38 in the disc 35. Thus two eggs inone hole 38 will not be scanned simultaneously, but the eg 40 in track1" of that hole will be scanned by the lower sensor 50 and the eg 41 intrack 2" of that hole will be scanned by the upper sensor 51, when thathole has been moved with the rotating disc in clockwise rotation.

Before describing the operation of the sorting apparatus more fully,reference will be made to other structural parts which include a deadegg compartment 55 located adjacent the periphery of the disc at theleft side of compartment 25 to receive dead eggs from the holes 38 inthe disc 35, and a live egg compartment 56 located adjacent theperiphery of the disc at the right side of compartment 25 to receivelive eggs from the holes 38 in the disc, as shown in FIGS. 1 and 4. Thecompartment 55 extends rearwardly and is provided with a dead egg outlet57 in its bottom. The backplate 30 and cradle 32 are provided withopenings 58 which permit passage of dead eggs from compartment 55 to theoutlet 57. Compartment 56 also extends rearwardly to a bottom opening 59which permits transfer of good eggs directly to hatch trays (not shown).

At each side of the reservoir 20 and egg and water compartment 25 arespray pipes 60 which communicate with the reservoir 20 and the eggcompartments 55, 56, respectively, for the purpose of flushing the wallsof the compartments and facilitating removal of the contents of thecompartments. The higher water level 21 in reservoir 20 as compared withthe water level 28 in the egg and water compartment 25 provides a smalldegree of pressure in the spray lines 60.

Between the periphery 36 of the disc 35 and the sensors 50 and 51 is aglass shield 61 curved to conform to the arc of the peripheral surface36 and mounted 5/1000 of an inch from said surface. This shield preventswater from the rotating disc 35 and water spatter caused by the air jets47 from falling on the sensor lenses. Water carried by the rotating discas well as ,the water spray from the air jets forms an oblong water bead62 that fuses itself between the peripheral surface of the rotating disc35 and shield 61, the spacing of 5/1000 inch between disc and shieldbeing sufficient to maintain a refreshed water bead and to preventdrying of the water into a film on the shield which would interfere withthe passage of the light beam from and to the sensors through theshield.

The operation of the sorting apparatus shown in FIGS. 1-9 is as follows:

Water and eggs to be sorted are placed in compartment 25 and water issupplied by pipes 21 to maintain the levels indicated at 22 and 28 incompartments 20 and 25 respectively. The disc 35 is rotated by a motor(not shown). The flow of water through the holes 38 in disc 35 andthrough the slots 33 in backplate 30 is sufficient to draw eggs into theholes 38 in the portion of the disc submerged in the water incompartment 25. The rib 31 closes the rearward open ends of the holes 38sufficiently to prevent eggs drawn into the holes from passing outthrough the rearward open ends of the holes. Thus the eggs, usually twoin a hole, are carried to and beyond the water level in the clockwiserotation of the disc.

When a hole 38 with eggs therein passes the sorting station located tothe left of the disc 35 in FIG. 1, the lower sensor 50 will scan the eg40 adjacent the forward opening 42, in track 1, and if the egg isopaque, the sensor's light beam will be reflected back to the sensorwhich instantly activates the air jet 47 opposite the conduit 46 leadinginto that hole 38, and blows egg 40 out of its hole, as indicated inFIG. 8. The egg 41 in the hole cannot be blown out simultaneouslybecause the rearward opening of that hole is closed by the stop 45. Asthe disc continues its rotary movement, the aforementioned hole 38 ismoved in the direction indicated in FIG. 8, and eg 41 remaining in thathole is scanned by the upper sensor 51. If it is opaque, the sensor andair jet function as described, and blow egg 41 out of the rearward openend 43, the other end being closed by stop 44. If both eggs 40, 41, in ahole are live eggs, neither will be ejected from the hole, but will becarried a distance of about 180 with the disc to a continuouslyfunctioning air jet 63 which blows all remaining eggs into the good eggcompartment 56.

The apparatus shown in FIGS. -12 differs in some respects from that ofFIGS. 1-8, particularly in that two sorting stations are employedinstead of one. In this modification, one sensor 66 is located at theleft of the disc 65 and a second sensor 67 is located at the right ofthe disc 65 as shown in FIG. 10. The disc 65 is similar to the disc 35heretofore described except that the holes 68 are restricted at one endas indicated at 69. Air ducts 70 communicate with the egg holes 68.Because the holes 68 are restricted at that end adjacent the rear of thedisc 65, eggs in the holes cannot pass through the holes and thereforethe rib 31 heretofore described for preventing passage of eggs throughholes 38, can be dispensed with. The backplate 38 and cradle 32, withspacer 29 between them, are shown in FIG. 1 1. Two shields 61 are used,one between the periphery of disc 65 and sensor 66, and the otherbetween disc 65 and sensor 67.

Two eggs 40 and 41, respectively, are drawn into holes 68, the eggs 40adjacent the front side of the disc 68 being in an annular row or track1 and the eggs 41 adjacent the rear side of the disc being in an annularrow or track 2. Each sorting station includes two egg receivingcompartments, designated live egg compartment 71, dead egg compartment72, at the left, and live egg compartment 73, dead compartment 74, atthe right of the apparatus. Exit holes are provided in the cradle andbackplate for passage of live and dead eggs from the compartments,designated 75, 76, 77, 78, respectively.

The operation of the modified apparatus shown in FIGS. 10-12 is asfollows: Eggs are picked up by the rotating disc 65 from the egg andwater compartment 25 and carried past the first sensor 66 which scanseggs in the row or track 1" adjacent the front of the disc. If a deadegg is sensed, the air jet 80 is activated to blow compressed air intothe air duct 70 and eject the dead egg into compartment 72. If the eggin that hole is a live egg, it will be ejected by constantly blowing airjet 81 into compartment 71 when the rotated disc has moved the distancebetween two adjacent holes 68. Eggs in the row or track 2" adjacent therear side of the disc 68 will be scanned by the sensor 67 at the rightof the apparatus, as viewed in FIG. 10. If the scanned egg is a deadegg, it will be ejected into the dead egg compartment 74 by the air jet82 communicating with air duct 70 and hole 68. Ifthe scanned egg is alive egg, it will remain in the hole until ejected by constantlyfunctioning air jet 83 into live egg compartment 73 at the right of theapparatus, as shown in FIG. 10.

FIG. 13 shows a diagram of the electrical circuits employed forcontrolling the apparatus of FIGS. 1-9 as well as the modifiedarrangement of FIGS. 10-12. FIG. 1 shows the manually operated controlbuttons on cabinet 26: off and on switch 85 for photoelectricamplifiers, off and on switch 86 for motor (not shown), sensitivitycontrol 87 for amplifier for air valve track 2, sensitivity control 88for amplifier for air valve track 1," indicator light 89 for egg track2" and indicator light 90 for egg track 1. In the diagram of FIG. 13,

the AC motor is designated 91, source of AC power 92, constant voltagetransformer 93 for photoelectric system, air valve 94 for track 1,"photoelectric amplifier 95 for egg track 1, air valve 96 for track 2,photoelectric amplifier 97 for egg track 2, motor switch 86, sensor 50(or 66) and sensor 51 (or 67).

The sorter uses air valves that are normally closed when no voltage isapplied. Air valves that are normally open when no voltage is appliedcould be used. In other words, the egg removal procedure described couldbe reversed, that is, the sensor could close the valve to shut off theair when a dead egg was encountered, allowing the dead egg to continuein its disc hole until removed by the air jet heretofore described forejecting a good egg, and the constantly functioning air jet could ejectall the bad eggs remaining in the disc holes.

The construction shown in FIGS. 1-8 and the modified apparatus of FIGS.10-13, achieve the exceptionally high sorting speed by subjecting twoeggs to scanning means at the same time, one of the two eggs beingcarried in one end or track of a disc hole while the other of the twoeggs is carried in the other end or second track of another hole. Theaccuracy of the scanning procedure is obtained by the provision of ashield 61 between the sensors 50, 51 and disc 35 (FIGS. 1-8) or of twoshields 61, one each between the sensor 66 and disc 65 and sensor 67 anddisc 65 (FIGS. 10-12), which hold the water bead 62 between shield anddisc periphery and thus provide a clear path for the light beam passingfrom and to the photoelectric cell of the sensor. The shield or shieldsalso prevent water spatter on the sensor lens or lenses.

1 claim:

1. Fish egg sorting apparatus for separating dead and live eggs,comprising a. a rotated disc provided with a series of holes whichextend through the disc from its front to rear faces adjacent theperipheral surface, each hole being capable of holding two eggs, one inthe front end of the hole and the other in the rear end of the hole,

b. photoelectric sensors located adjacent the disc periphery, one inposition to scan an egg in the front end of a disc hole and the other inposition to scan an egg in the rear end of a disc hole,

c. egg-ejection means activated by a sensor when the sensor scans a deadegg, and

d. means for ejecting good eggs from the holes.

2. Fish egg sorting apparatus defined by claim 1, which includes a waterand egg compartment open at its top in which the disc is partiallysubmerged, an arcuate surfaced cradle closely beneath the disc, and aslotted backplate which permits flow of water through the holes in thedisc and slots in the backplate whereby eggs are drawn into the discholes.

3. Fish egg sorting apparatus defined by claim 1, which includes a waterand egg compartment open at its top in which the disc is partiallysubmerged, an arcuate surfaced cradle closely beneath the disc, and abackplate with attached arcuate rib located rearwardly of the disc inthe water and egg compartment in a position wherein the ribsubstantially registers with the holes in the submerged part of thedisc.

4. Fish egg sorting apparatus defined by claim 1, which includesseparate compartments for receiving live eggs and dead eggs, and bottomopenings in the egg compartments for discharge of separated eggs.

5. Fish egg sorting apparatus defined by claim I, in which the sensorsare located in different horizontal planes adjacent the peripheralsurface of the disc.

6. Fishegg sorting apparatus defined by claim 1, in which the sensorsare of the reflective type producing a light beam which is reflected byan opaque fish egg and the reflected beam passes back into the sensor toactivate means which eject the dead egg from a disc hole.

7. Fish egg sorting apparatus defined by claim 1, in which the sensorsare located to direct their beams through the peripheral surface of thedisc.

8. Fish egg sorting apparatus for separating dead and live eggs,comprising a. a rotated disc provided with a series of holes whichextend through the disc from its front to rear faces adjacent theperipheral surface of the disc, each hole being capable of holding twoeggs, one in the front end of the hole and the other in the rear end ofthe hole whereby the eggs form an annular front row and an annular rearrow,

b. photoelectric sensors located adjacent the disc periphery indifferent horizontal planes, one in position to scan an egg located inthe annular front row and the other in position to scan an egg in theannular rear row,

0. an air duct extending through the disc into communication with eachhole,

d. two compressed air jets communicating with air ducts each activatedby a sensor when the sensor scans a dead egg in a disc hole, and

e. means for ejecting good eggs from the holes.

9. Fish egg sorting apparatus defined by claim 8, which includes a waterand egg compartment open at its top in which the disc is partiallysubmerged, an arcuate surfaced cradle closely beneath the disc, and aslotted backplate which permits flow of water through the holes in thedisc and slots in the backplate whereby eggs are drawn into the discholes.

10. Fish egg sorting apparatus defined by claim 8, which includes awater and egg compartment open at its top in which the disc is partiallysubmerged, an arcuate surfaced cradle closely beneath the disc, and abackplate with attached arcuate rib located rearwardly of the disc inthe water and egg compartment in a position wherein the ribsubstantially registers with the holes in the submerged part of thedisc.

11. Fish egg sorting apparatus defined by claim 8, which includesseparate compartments for receiving live eggs and dead eggs, and bottomopenings in the egg compartments for discharge of separated eggs.

12. Fish egg sorting apparatus for separating dead and live eggs,comprising a. a rotated disc provided with a series of holes whichextend through the disc and into which are drawn eggs to be sorted,

a photoelectric sensor located adjacent the disc periphery in positionto direct its light beam through the disc to an egg in a hole in thedisc,

c. and a transparent shield between the disc periphery and the sensor,the shield being located closely adjacent the peripheral surface of thedisc but slightly spaced therefrom to hold a water bead between the discand shield for providing a clear path for passage of the sensor beamthrough the shield and water bead.

13. Fish egg sorting apparatus defined by claim 12 which includesegg-ejecting means, and in which the sensor is of the reflective typeincluding a light beam reflected by an opaque fish egg and the reflectedbeam passes back into the sensor to activate egg-ejecting means, saidwater bead providing a clear path for passage of the sensor beam throughthe sensor lens, shield, water bead, and disc periphery, and returnpassage of the sensor beam through the disc periphery.

14. Fish egg sorting apparatus defined by claim 12, in which the shieldconforms generally to the arcuate peripheral surface of the disc and isspaced approximately 5/1000 inch from the disc periphery.

1. Fish egg sorting apparatus for separating dead and live eggs,comprising a. a rotated disc provided with a series of holes whichextend through the disc from its front to rear faces adjacent theperipheral surface, each hole being capable of holding two eggs, one inthe front end of the hole and the other in the rear end of the hole, b.photoelectric sensors located adjacent the disc periphery, one inposition to scan an egg in the front end of a disc hole and the other inposition to scan an egg in the rear end of a disc hole, c. egg-ejectionmeans activated by a sensor when the sensor scans a dead egg, and d.means for ejecting good eggs from the holes.
 2. Fish egg sortingapparatus defined by claim 1, which includes a water and egg compartmentopen at its top in which the disc is partially submerged, an arcuatesurfaced cradle closely beneath the disc, and a slotted backplate whichpermits flow of water through the holes in the disc and slots in thebackplate whereby eggs are drawn into the disc holes.
 3. Fish eggsorting apparatus defined by claim 1, which includes a water and eggcompartment open at its top in which the disc is partially submerged, anarcuate surfaced cradle closely beneath the disc, and a backplate withattached arcuate rib located rearwardly of the disc in the water and eggcompartment in a position wherein the rib substantially registers withthe holes in the submerged part of the disc.
 4. Fish egg sortingapparatus defined by claim 1, which includes separate compartments forreceiving live eggs and dead eggs, and bottom openings in the eggcompartments for discharge of separated eggs.
 5. Fish egg sortingapparatus defined by claim 1, in which the sensors are located indifferent horizontal planes adjacent the peripheral surface of the disc.6. Fish egg sorting apparatus defined by claim 1, in which the sensorsare of the reflective type producing a light beam which is reflected byan opaque fish egg and the reflected beam passes back into the sensor toactivate means which eject the dead egg from a disc hole.
 7. Fish eggsorting apparatus defined by claim 1, in which the sensors are locatedto direct their beams through the peripheral surface of the disc. 8.Fish egg sorting apparatus for separating dead and live eggs, comprisinga. a rotated disc provided with a series of holes which extend throughthe disc from its front to rear faces adjacent the peripheral surface ofthe disc, each hole being capable of holding two eggs, one in the frontend of the hole and the other in the rear end of the hole whereby theeggs form an annular front row and an annular rear row, b. photoelectricsensors located adjacent the disc periphery in different horizontalplanes, one in position to scan an egg located in the annular front rowand the other in position to scan an egg in the annular rear row, c. anair duct extending through the disc into communication with each hole,d. two compressed air jets communicating with air ducts each activatedby a sensor when the sensor scans a dead egg in a disc hole, and e.means for ejecting good eggs from the holes.
 9. Fish egg sortingapparaTus defined by claim 8, which includes a water and egg compartmentopen at its top in which the disc is partially submerged, an arcuatesurfaced cradle closely beneath the disc, and a slotted backplate whichpermits flow of water through the holes in the disc and slots in thebackplate whereby eggs are drawn into the disc holes.
 10. Fish eggsorting apparatus defined by claim 8, which includes a water and eggcompartment open at its top in which the disc is partially submerged, anarcuate surfaced cradle closely beneath the disc, and a backplate withattached arcuate rib located rearwardly of the disc in the water and eggcompartment in a position wherein the rib substantially registers withthe holes in the submerged part of the disc.
 11. Fish egg sortingapparatus defined by claim 8, which includes separate compartments forreceiving live eggs and dead eggs, and bottom openings in the eggcompartments for discharge of separated eggs.
 12. Fish egg sortingapparatus for separating dead and live eggs, comprising a. a rotateddisc provided with a series of holes which extend through the disc andinto which are drawn eggs to be sorted, b. a photoelectric sensorlocated adjacent the disc periphery in position to direct its light beamthrough the disc to an egg in a hole in the disc, c. and a transparentshield between the disc periphery and the sensor, the shield beinglocated closely adjacent the peripheral surface of the disc but slightlyspaced therefrom to hold a water bead between the disc and shield forproviding a clear path for passage of the sensor beam through the shieldand water bead.
 13. Fish egg sorting apparatus defined by claim 12 whichincludes egg-ejecting means, and in which the sensor is of thereflective type including a light beam reflected by an opaque fish eggand the reflected beam passes back into the sensor to activateegg-ejecting means, said water bead providing a clear path for passageof the sensor beam through the sensor lens, shield, water bead, and discperiphery, and return passage of the sensor beam through the discperiphery.
 14. Fish egg sorting apparatus defined by claim 12, in whichthe shield conforms generally to the arcuate peripheral surface of thedisc and is spaced approximately 5/1000 inch from the disc periphery.